This material is reproduced from J. H. Clark, Green and Sustainable Chemistry: An Introduction, in Green and Sustainable Medicinal Chemistry: Methods, Tools and Strategies for the 21st Century Pharmaceutical Industry, The Royal Society of Chemistry, 2016, ch. 1, pp. 1-11.
It is copyright to the Royal Society of Chemistry (RSC) and is reproduced here with their express permission. If you wish to reproduce it elsewhere you must obtain similar permission from the RSC.
Green chemistry is quite well defined by the twelve principles of Anastas and Warner.  These principles focus on how to make a greener synthetic process, chemical product or chemical reaction, resulting in minimising its environmental impact. The twelve principles gained prominence in 1998 but as the scope of green chemistry has broadened, so have the potential applications. This is explored further in the lesson Twelve principles for the twenty-first century.
Green engineering can be defined as the design, commercialisation and use of processes and products that are feasible and economical, while minimising generation of pollution at source and risk to human health and the environment . Green engineering uses the tools of recycling, process intensification and design optimisation to maximise the efficiency of a process, and reduce its negative impact on the environment. This approach evaluates the manufacturing process as a system and seeks to optimise its design, and in the truest sense, incorporates the concepts of life-cycle analysis and environmental economics into an appropriate evaluation of the overall environmental impact. The development of a set of metrics is required that appropriately evaluates the environmental parameters that we seek to control.
Sustainable design looks even more broadly to try to understand the relationships between the manufacturing system and the ecosystem. Sustainability focuses on the triple bottom line: the integration of ecological integrity, societal responsibility and economic viability. This applies the broadest level systems approach, looking at the planet as the system of interest. In order to optimise design at this scale, new ways of measuring human impacts on the environment are required.
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